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Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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10 pages, 3280 KiB  
Article
Electrochromic Polymers: From Electrodeposition to Hybrid Solid Devices
by Hadarou Sare and Dongmei Dong
Energies 2024, 17(1), 232; https://doi.org/10.3390/en17010232 - 1 Jan 2024
Cited by 3 | Viewed by 1292
Abstract
This paper reports on the linear colorimetric and electrochromic (EC) characteristics of electrodeposited polyaniline (PANI) films. This paper also investigates the infrared EC properties of acid-doped PANI films. The electrochemical polymerization method was employed to create a porous and thin PANI film layer [...] Read more.
This paper reports on the linear colorimetric and electrochromic (EC) characteristics of electrodeposited polyaniline (PANI) films. This paper also investigates the infrared EC properties of acid-doped PANI films. The electrochemical polymerization method was employed to create a porous and thin PANI film layer onto PET-ITO substrates. This layer was capped with WO3 film to create a gel electrolyte sandwich structure that demonstrates the compatibility of PANI films with cathodic WO3 films in full devices. The electrodeposition of the film was fabricated by applying different voltages and time, with the optimal film quality achieved with the 1.7 V voltage and a 20 min deposition period. The surface morphology, optical performance, electrochemical behavior, and molecular structure evolution are comprehensively studied in this work. The linear colorimetric behaviors and the corresponding significant changes in the structure in Raman spectra build direct strong quantitative relations in EC polymers. The well-defined oxidation and reduction peaks observed in the cyclic voltammetry indicate the ion-diffusion dominant process in the electrochromism of PANI. Significant transitions between the benzene and quinone phases in the Raman spectra are found in the bleached and colored states of polymers. This study enhances the understanding of PANI film structure and electrochemical and associated optical properties, providing more insights into the dual-function EC charge storage polymers and other energy-related functional materials. Full article
(This article belongs to the Special Issue Thin Films for Renewable Energy Production, Storage and Conversion)
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30 pages, 20623 KiB  
Article
Cooling Strategy Optimization of Cylindrical Lithium-Ion Battery Pack via Multi-Counter Cooling Channels
by Hyeonchang Jeon, Seokmoo Hong, Jinwon Yun and Jaeyoung Han
Energies 2023, 16(23), 7860; https://doi.org/10.3390/en16237860 - 30 Nov 2023
Cited by 1 | Viewed by 2208
Abstract
This study focused on the design of a battery pack cooling channel based on a Tesla Model S electric car. This study aimed to achieve a balance between cooling efficiency and pressure drop while maintaining safe and optimal operating temperatures for the batteries. [...] Read more.
This study focused on the design of a battery pack cooling channel based on a Tesla Model S electric car. This study aimed to achieve a balance between cooling efficiency and pressure drop while maintaining safe and optimal operating temperatures for the batteries. A cooling channel design similar to the basic type employed in the Tesla Model S using 448 cylindrical Li-ion batteries was considered. Consequently, important parameters, such as the maximum temperature and temperature difference in the battery cells in a module, as well as the pressure drop of the coolant, were analyzed. In addition, the characteristics of the temperature changes in each cooling channel shape were investigated. The temperature limit for the battery in a module and the temperature limit difference were set to 40 °C and 5 °C, respectively, to evaluate the performance of the cooling system. Further, the effects of discharge rates (3C and 5C), cooling channel shapes (counter flow and parallel types), and coolant inlet velocities (0.1, 0.2, 0.3, and 0.4 m/s) on battery thermal management were analyzed. The results revealed that the parallel type channel yielded a lower pressure drop than the basic type channel; however, it was not as effective in removing heat from the battery. In contrast, the counter flow type channel effectively removed heat from the batteries with a higher coolant pressure drop in the channel. Therefore, a multi-counter flow type cooling channel combining the advantages of both these channels was proposed to decrease the pressure drop while maintaining appropriate operating temperatures for the battery module. The proposed cooling channel exhibited an excellent cooling performance with lower power consumption and better heat transfer characteristics. However, relatively minimal differences were confirmed for the maximum temperature and temperature difference in the battery module compared with the counter flow type. Therefore, the proposed cooling channel type can be implemented to ensure the optimal temperature operation of the battery module and to decrease system power consumption. Full article
(This article belongs to the Section D2: Electrochem: Batteries, Fuel Cells, Capacitors)
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32 pages, 8722 KiB  
Review
Power Generation with Renewable Energy and Advanced Supercritical CO2 Thermodynamic Power Cycles: A Review
by Xinyu Zhang and Yunting Ge
Energies 2023, 16(23), 7781; https://doi.org/10.3390/en16237781 - 26 Nov 2023
Cited by 3 | Viewed by 2206
Abstract
Supercritical CO2 (S-CO2) thermodynamic power cycles have been considerably investigated in the applications of fossil fuel and nuclear power generation systems, considering their superior characteristics such as compactness, sustainability, cost-effectiveness, environmentally friendly working fluid and high thermal efficiency. They can [...] Read more.
Supercritical CO2 (S-CO2) thermodynamic power cycles have been considerably investigated in the applications of fossil fuel and nuclear power generation systems, considering their superior characteristics such as compactness, sustainability, cost-effectiveness, environmentally friendly working fluid and high thermal efficiency. They can be potentially integrated and applied with various renewable energy systems for low-carbon power generation, so extensive studies in these areas have also been conducted substantially. However, there is a shortage of reviews that specifically concentrate on the integrations of S-CO2 with renewable energy, encompassing biomass, solar, geothermal and waste heat. It is thus necessary to provide an update and overview of the development of S-CO2 renewable energy systems and identify technology and integration opportunities for different types of renewable resources. Correspondingly, this paper not only summarizes the advantages of CO2 working fluid, design layouts of S-CO2 cycles and classifications of renewable energies to be integrated but also reviews the recent research activities and studies carried out worldwide on advanced S-CO2 power cycles with renewable energy. Moreover, the performance and development of various systems are well grouped and discussed. Full article
(This article belongs to the Collection Renewable Energy and Energy Storage Systems)
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27 pages, 2130 KiB  
Review
Trends and Evolution of the GIS-Based Photovoltaic Potential Calculation
by Sebastiano Anselmo and Maria Ferrara
Energies 2023, 16(23), 7760; https://doi.org/10.3390/en16237760 - 24 Nov 2023
Cited by 2 | Viewed by 1840
Abstract
In the current framework of energy transition, renewable energy production has gained a renewed relevance. A set of 75 papers was selected from the existing literature and critically analyzed to understand the main inputs and tools used to calculate solar energy and derive [...] Read more.
In the current framework of energy transition, renewable energy production has gained a renewed relevance. A set of 75 papers was selected from the existing literature and critically analyzed to understand the main inputs and tools used to calculate solar energy and derive theoretical photovoltaic production based on geographic information systems (GISs). A heterogeneous scenario for solar energy estimation emerged from the analysis, with a prevalence of 2.5D tools—mainly ArcGIS and QGIS—whose calculation is refined chiefly by inputting weather data from databases. On the other hand, despite some minor changes, the formula for calculating the photovoltaic potential is widely acknowledged and includes solar energy, exploitable surface, performance ratio, and panel efficiency. While sectorial studies—targeting a specific component of the calculation—are sound, the comprehensive ones are generally problematic due to excessive simplification of some parts. Moreover, validation is often lacking or, when present, only partial. The research on the topic is in constant evolution, increasingly moving towards purely 3D models and refining the estimation to include the time component—both in terms of life cycle and variations between days and seasons. Full article
(This article belongs to the Special Issue Emerging Trends in Energy and Environmental Design Integrating New Services and Tools for Smart Cities and Smart Buildings)
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22 pages, 1331 KiB  
Review
The Allam Cycle: A Review of Numerical Modeling Approaches
by Fabrizio Reale
Energies 2023, 16(22), 7678; https://doi.org/10.3390/en16227678 - 20 Nov 2023
Cited by 2 | Viewed by 2596
Abstract
In recent years supercritical CO2 power plants have seen a growing interest in a wide range of applications (e.g., nuclear, waste heat recovery, solar concentrating plants). The Allam Cycle, also known as the Allam-Fetvedt or NET Power cycle, seems to be one [...] Read more.
In recent years supercritical CO2 power plants have seen a growing interest in a wide range of applications (e.g., nuclear, waste heat recovery, solar concentrating plants). The Allam Cycle, also known as the Allam-Fetvedt or NET Power cycle, seems to be one of the most interesting direct-fired sCO2 cycles. It is a semi-closed loop, high-pressure, low-pressure ratio, recuperated, direct-fired with oxy-combustion, trans-critical Brayton cycle. Numerical simulations play a key role in the study of this novel cycle. For this reason, the aim of this review is to offer the reader a wide array of modeling solutions, emphasizing the ones most frequently employed and endeavoring to provide guidance on which choices seem to be deemed most appropriate. Furthermore, the review also focuses on the system’s performance and on the opportunities related to the integration of the Allam cycle with a series of processes, e.g., cold energy storage, LNG regasification, biomass or coal gasification, and ammonia production. Full article
(This article belongs to the Section B: Energy and Environment)
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29 pages, 5023 KiB  
Review
Review on New-Generation Batteries Technologies: Trends and Future Directions
by Khaled Itani and Alexandre De Bernardinis
Energies 2023, 16(22), 7530; https://doi.org/10.3390/en16227530 - 11 Nov 2023
Cited by 20 | Viewed by 9996
Abstract
Battery technologies have recently undergone significant advancements in design and manufacturing to meet the performance requirements of a wide range of applications, including electromobility and stationary domains. For e-mobility, batteries are essential components in various types of electric vehicles (EVs), including battery electric [...] Read more.
Battery technologies have recently undergone significant advancements in design and manufacturing to meet the performance requirements of a wide range of applications, including electromobility and stationary domains. For e-mobility, batteries are essential components in various types of electric vehicles (EVs), including battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and fuel cell electric vehicles (FCEVs). These EVs rely on diverse charging systems, including conventional charging, fast-charging, and vehicle-to-everything (V2X) systems. In stationary applications, batteries are increasingly being employed for the electrical management of micro/smart grids as transient buffer energy storage. Batteries are commonly used in conjunction with power electronic interfaces to adapt to the specific requirements of various applications. Furthermore, power electronic interfaces to batteries themselves have evolved technologically, resulting in more efficient, thermally efficient, compact, and robust power converter architectures. This article offers a comprehensive review of new-generation battery technologies. The topic is approached from the perspective of applications, emerging trends, and future directions. The article explores new battery technologies utilizing innovative electrode and electrolyte materials, their application domains, and technological limitations. In conclusion, a discussion and analysis are provided, synthesizing the technological evolution of batteries while highlighting new trends, directions, and prospects. Full article
(This article belongs to the Section D2: Electrochem: Batteries, Fuel Cells, Capacitors)
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23 pages, 4327 KiB  
Article
Model-Driven Membrane Electrode Assembly Design for High-Performing Open-Cathode Polymer Electrolyte Membrane Fuel Cells
by Anand Sagar, Sachin Chugh and Erik Kjeang
Energies 2023, 16(22), 7472; https://doi.org/10.3390/en16227472 - 7 Nov 2023
Cited by 1 | Viewed by 1019
Abstract
Open-cathode fuel cells use air cooling to effectively reduce system cost. However, due to the challenging hygrothermal environment, they generally suffer from low performance compared to conventional, liquid-cooled cells. A pre-validated, three-dimensional computational model is used in the present work to determine the [...] Read more.
Open-cathode fuel cells use air cooling to effectively reduce system cost. However, due to the challenging hygrothermal environment, they generally suffer from low performance compared to conventional, liquid-cooled cells. A pre-validated, three-dimensional computational model is used in the present work to determine the effects of different sub-component designs, namely the polymeric membrane, composition of the cathode catalyst layer (CCL), and structure of the cathode microporous layer (CMPL), on the performance of an open-cathode fuel cell. This comprehensive parametric study performed on a total of 90 cases shows the increment in current density to be 7% and 31% by improvising the membrane and CCL design, respectively, at 0.6 V. A steep increase of 87% is also achieved by strategically modifying the CMPL design at 0.4 V operation. An overall increment of 119% and 131% in current density is achieved for the best membrane electrode assembly (MEA) design at 0.6 and 0.4 V, respectively, as compared to the baseline design. These improvements are achieved by collective improvements in kinetics, oxygen mass transport, ohmic resistance, self-heating, and water retention in the ionomer phase. The proposed MEA design could facilitate open-cathode fuel cell stacks with 2× higher power output or 56% lower weight and materials cost for a given power demand. Full article
(This article belongs to the Section A5: Hydrogen Energy)
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26 pages, 5952 KiB  
Article
Equipment- and Time-Constrained Data Acquisition Protocol for Non-Intrusive Appliance Load Monitoring
by Konstantinos Koasidis, Vangelis Marinakis, Haris Doukas, Nikolaos Doumouras, Anastasios Karamaneas and Alexandros Nikas
Energies 2023, 16(21), 7315; https://doi.org/10.3390/en16217315 - 28 Oct 2023
Cited by 1 | Viewed by 1476
Abstract
Energy behaviours will play a key role in decarbonising the building sector but require the provision of tailored insights to assist occupants to reduce their energy use. Energy disaggregation has been proposed to provide such information on the appliance level without needing a [...] Read more.
Energy behaviours will play a key role in decarbonising the building sector but require the provision of tailored insights to assist occupants to reduce their energy use. Energy disaggregation has been proposed to provide such information on the appliance level without needing a smart meter plugged in to each load. However, the use of public datasets with pre-collected data employed for energy disaggregation is associated with limitations regarding its compatibility with random households, while gathering data on the ground still requires extensive, and hitherto under-deployed, equipment and time commitments. Going beyond these two approaches, here, we propose a novel data acquisition protocol based on multiplexing appliances’ signals to create an artificial database for energy disaggregation implementations tailored to each household and dedicated to performing under conditions of time and equipment constraints, requiring that only one smart meter be used and for less than a day. In a case study of a Greek household, we train and compare four common algorithms based on the data gathered through this protocol and perform two tests: an out-of-sample test in the artificially multiplexed signal, and an external test to predict the household’s appliances’ operation based on the time series of a real total consumption signal. We find accurate monitoring of the operation and the power consumption level of high-power appliances, while in low-power appliances the operation is still found to be followed accurately but is also associated with some incorrect triggers. These insights attest to the efficacy of the protocol and its ability to produce meaningful tips for changing energy behaviours even under constraints, while in said conditions, we also find that long short-term memory neural networks consistently outperform all other algorithms, with decision trees closely following. Full article
(This article belongs to the Special Issue Energy Efficiency of the Buildings II)
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14 pages, 3847 KiB  
Article
Combined Effect of In Situ Stress Level and Bedding Anisotropy on Hydraulic Fracture Vertical Growth in Deep Marine Shale Revealed via CT Scans and Acoustic Emission
by Peng Guo, Xiao Li, Shouding Li and Tianqiao Mao
Energies 2023, 16(21), 7270; https://doi.org/10.3390/en16217270 - 26 Oct 2023
Cited by 2 | Viewed by 1279
Abstract
The economic exploitation of unconventional gas and oil in deep shale relies closely on effective hydraulic fracturing stimulations. However, the fracturing operations of deep shale reservoirs face challenges of insufficient fracture growth and a rapid decline in productivity due to the increasing in [...] Read more.
The economic exploitation of unconventional gas and oil in deep shale relies closely on effective hydraulic fracturing stimulations. However, the fracturing operations of deep shale reservoirs face challenges of insufficient fracture growth and a rapid decline in productivity due to the increasing in situ stress level. In addition, the shale strata on the margin of the Sichuan Basin are frequently folded and faulted, and the change in bedding inclinations significantly complicates the process of hydraulic fracturing. The investigation of the combined effect of the in situ stress level and bedding anisotropy on the hydraulic fracture configuration is vital for fracturing engineering design. To analyze this, we conducted hydraulic fracturing tests on shale cores to simulate the hydraulic fracture initiation and growth from a horizontally positioned perforation. By using acoustic emission detection and CT scans, the influence of natural stress levels and the angle of the shale’s bedding on the process of hydraulic fracturing in shale and the resulting fracture geometry were analyzed. The results showed that the area of hydraulic fracture under a higher stress level (σ1 = 50 MPa, σ3 = 40 MPa) was about 13%~23% smaller than that created under the lower stress level (σ1 = 30 MPa, σ3 = 20 MPa) when the bedding angle was smaller than 60°. With the increase in bedding angle, the curves of the fracture area and fracture network index under two different stress levels presented similar decreasing trends. Also, the time from micro-crack generation to sample breakdown was significantly reduced when the bedding orientation changed from the horizontal to vertical position. The increasing stress level significantly increased the breakdown pressure. In particular, the fracturing of shale samples with bedding angles of 0° and 30° required a higher fluid pressure and released more energy than samples with larger bedding inclinations. Additionally, the measurement of the sample radial deformation indicated that the hydraulic fracture opening extent was reduced by about 46%~81% with the increasing stress level. Full article
(This article belongs to the Topic Structural Characterization and Hydraulic Fracturing Responses of Deep-Buried Geomaterials)
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22 pages, 12874 KiB  
Article
An Experimental and Detailed Kinetics Modeling Study of Norbornadiene in Hydrogen and Methane Mixtures: Ignition Delay Time and Spectroscopic CO Measurements
by Matthew G. Sandberg, Claire M. Grégoire, Darryl J. Mohr, Olivier Mathieu and Eric L. Petersen
Energies 2023, 16(21), 7278; https://doi.org/10.3390/en16217278 - 26 Oct 2023
Cited by 1 | Viewed by 1201
Abstract
High-energy-density compounds such as norbornadiene (NBD) are being considered as potential cost-effective fuel additives, or partial replacements, for high-speed propulsion applications. To assess the ability of NBD to influence basic fuel reactivity enhancement and to build a database for developing future NBD kinetics [...] Read more.
High-energy-density compounds such as norbornadiene (NBD) are being considered as potential cost-effective fuel additives, or partial replacements, for high-speed propulsion applications. To assess the ability of NBD to influence basic fuel reactivity enhancement and to build a database for developing future NBD kinetics models, ignition delay times were measured in two shock-tube facilities at Texas A&M University for H2/O2, CH4/O2, H2/NBD/O2, and CH4/NBD/O2 mixtures (ϕ = 1) that were highly diluted in argon. The reflected-shock temperatures ranged from 1014 to 2227 K, and the reflected-shock pressures remained near 1 atm for all of the experiments, apart from the hydrogen mixtures, which were also tested near 7 atm, targeting the second-explosion limit. The molar concentrations of NBD were supplemented to the baseline mixtures representing 1–2% of the fuel by volume. A chemiluminescence diagnostic was used to track the time history of excited hydroxyl radical (OH*) emission, which was used to define the ignition delay time at the sidewall location. Spectroscopic CO data were also obtained using a tunable quantum cascade laser to complement both the ignition and the chemiluminescence data. The CH4/O2 mixtures containing NBD demonstrated reduced ignition delay times, with a pronounced effect at lower temperatures. Conversely, this additive increased the ignition delay time dramatically in the H2/O2 mixture, which was attributed to changes in the fundamental chemistry with the introduction of molecules containing carbon bonds, which require stronger activation energies for ignition. Correlations were developed to predict the ignition delay time, which depends on species concentration, temperature, and pressure. Additionally, one tentative mechanism was tested, combining base chemistry from NUIGMech 1.1 with pyrolysis and oxidation reactions for NBD using the recent efforts from experimental and theoretical literature studies. The numerical predictions show that the rapid decomposition of NBD provides a pool of active H-radicals, significantly increasing the reactivity of methane. This study represents the first set of gas-phase ignition and CO time-history data measured in a shock tube for hydrogen and methane mixtures containing the additive NBD. Full article
(This article belongs to the Special Issue Advances in Fuels and Combustion)
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17 pages, 22879 KiB  
Article
The Influence of the Type and Condition of Road Surfaces on the Exhaust Emissions and Fuel Consumption in the Transport of Timber
by Andrzej Ziółkowski, Paweł Fuć, Piotr Lijewski, Maciej Bednarek, Aleks Jagielski, Władysław Kusiak and Joanna Igielska-Kalwat
Energies 2023, 16(21), 7257; https://doi.org/10.3390/en16217257 - 25 Oct 2023
Cited by 3 | Viewed by 1875
Abstract
Owing to society’s growing ecological awareness, researchers and car manufacturers have increasingly been focusing on the adverse impact of transport on the environment. Many scientific publications have been published addressing the influence of a variety of factors on the exhaust emissions generated by [...] Read more.
Owing to society’s growing ecological awareness, researchers and car manufacturers have increasingly been focusing on the adverse impact of transport on the environment. Many scientific publications have been published addressing the influence of a variety of factors on the exhaust emissions generated by vehicles and machinery. In this paper, the authors present an analysis of the exhaust emissions of components such as CO, THC, and NOx in relation to the type and condition of the road surface. The analysis was performed on a heavy-duty truck designed for carriage of timber. The investigations were carried out with the use of the PEMS equipment (portable emission measurement system) on bitumen-paved roads and unpaved forest access roads. The portable measurement system allowed for an accurate determination of the influence of the road conditions on the operating parameters of the vehicle powertrain and its exhaust emissions. Additionally, the authors present the influence of the type of road surface on the vehicle fuel consumption calculated based on the carbon balance method. Full article
(This article belongs to the Special Issue CO2 Emissions from Vehicles (Volume II))
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28 pages, 2763 KiB  
Review
Quality of Service and Associated Communication Infrastructure for Electric Vehicles
by Rajeshkumar Ramraj, Ehsan Pashajavid, Sanath Alahakoon and Shantha Jayasinghe
Energies 2023, 16(20), 7170; https://doi.org/10.3390/en16207170 - 20 Oct 2023
Cited by 5 | Viewed by 1777
Abstract
Transportation electrification is pivotal for achieving energy security and emission reduction goals. Electric vehicles (EVs) are at the forefront of this transition, driving the development of new EV technologies and infrastructure. As this trend gains momentum, it becomes essential to enhance the quality [...] Read more.
Transportation electrification is pivotal for achieving energy security and emission reduction goals. Electric vehicles (EVs) are at the forefront of this transition, driving the development of new EV technologies and infrastructure. As this trend gains momentum, it becomes essential to enhance the quality of service (QoS) of EVs to encourage their widespread adoption. This paper has been structured with two primary aims to effectively address the above timely technological needs. Firstly, it comprehensively reviews the various QoS factors that influence EVs’ performance and the user experience. Delving into these factors provides valuable insights into how the QoS can be improved, thereby fostering the increased use of EVs on our roads. In addition to the QoS, this paper also explores recent advancements in communication technologies vital for facilitating in-formation exchanges between EVs and charging stations. Efficient communication systems are crucial for optimizing EV operations and enhancing user experiences. This paper presents expert-level technical details in an easily understandable manner, making it a valuable resource for researchers dedicated to improving the QoS of EV communication systems, who are tirelessly working towards a cleaner, more efficient future in transportation. It consolidates the current knowledge in the field and presents the latest discoveries and developments, offering practical insights for enhancing the QoS in electric transportation. A QoS parameter reference map, a detailed classification of QoS parameters, and a classification of EV communication technology references are some of the key contributions of this review paper. In doing so, this paper contributes to the broader objectives of promoting transportation electrification, enhancing energy security, and reducing emissions. Full article
(This article belongs to the Special Issue Electric Vehicle Charging: Social and Technical Issues)
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19 pages, 5226 KiB  
Article
Multi-Scale Seismic Measurements for Site Characterization and CO2 Monitoring in an Enhanced Oil Recovery/Carbon Capture, Utilization, and Sequestration Project, Farnsworth Field, Texas
by George El-kaseeh and Kevin L. McCormack
Energies 2023, 16(20), 7159; https://doi.org/10.3390/en16207159 - 19 Oct 2023
Cited by 1 | Viewed by 1239
Abstract
To address the challenges of climate change, significantly more geologic carbon sequestration projects are beginning. The characterization of the subsurface and the migration of the plume of supercritical carbon dioxide are two elements of carbon sequestration that can be addressed through the use [...] Read more.
To address the challenges of climate change, significantly more geologic carbon sequestration projects are beginning. The characterization of the subsurface and the migration of the plume of supercritical carbon dioxide are two elements of carbon sequestration that can be addressed through the use of the available seismic methods in the oil and gas industry. In an enhanced oil recovery site in Farnsworth, TX, we employed three separate seismic techniques. The three-dimensional (3D) surface seismic survey required significant planning, design, and processing, but produces both a better understanding of the subsurface structure and a three-dimensional velocity model, which is essential for the second technique, a timelapse vertical seismic profile, and the third technique, cross-well seismic tomography. The timelapse 3D Vertical Seismic Profile (3D VSP) revealed both significant changes in the reservoir between the second and third surveys and geo-bodies that may represent the extent of the underground carbon dioxide. The asymmetry of the primary geo-body may indicate the preferential migration of the carbon dioxide. The third technique, cross-well seismic tomography, suggested a strong correlation between the well logs and the tomographic velocities, but did not observe changes in the injection interval. Full article
(This article belongs to the Special Issue Forecasting CO2 Sequestration with Enhanced Oil Recovery II)
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19 pages, 3389 KiB  
Article
Hydrothermal but Not Mechanical Pretreatment of Wastewater Algae Enhanced Anaerobic Digestion Energy Balance due to Improved Biomass Disintegration and Methane Production Kinetics
by Pavlo Bohutskyi, Duc Phan, Ruth E. Spierling and Trygve J. Lundquist
Energies 2023, 16(20), 7146; https://doi.org/10.3390/en16207146 - 19 Oct 2023
Cited by 2 | Viewed by 1309
Abstract
This study used pilot-scale high-rate algae ponds to assess algal–bacteria biomass productivity and wastewater nutrient removal as well as the impact of mechanical and hydrothermal pretreatments on biomass disintegration, methane production kinetics, and anaerobic digestion (AD) energy balance. Mechanical pretreatment had a minor [...] Read more.
This study used pilot-scale high-rate algae ponds to assess algal–bacteria biomass productivity and wastewater nutrient removal as well as the impact of mechanical and hydrothermal pretreatments on biomass disintegration, methane production kinetics, and anaerobic digestion (AD) energy balance. Mechanical pretreatment had a minor effect on biomass disintegration and methane production. By contrast, hydrothermal pretreatment significantly reduced particle size and increased the solubilized organic matter content by 3.5 times. The methane yield and production rate increased by 20–55% and 20–85%, respectively, with the highest values achieved after pretreatment at 121 °C for 60 min. While the 1st-order and pseudo-1st-order reaction equation models fitted methane production from untreated biomass best (R2 > 0.993), the modified Gompertz sigmoidal-type model provided a superior fit for hydrothermally pretreated algae (R2 ≥ 0.99). The AD energy balance revealed that hydrothermal pretreatment improved the total energy output by 25–40%, with the highest values for volume-specific and mass-specific total energy outputs reaching 0.23 kW per digester m3 and 2.3 MW per ton of biomass volatile solids. Additionally, net energy recovery (energy output per biomass HHV) increased from 20% for untreated algae to 32–34% for hydrothermally pretreated algae, resulting in net energy ratio and net energy efficiency of 2.14 and 68%, respectively. Full article
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19 pages, 761 KiB  
Article
A Stochastic Model of Anomalously Fast Transport of Heat Energy in Crystalline Bodies
by Łukasz Stępień and Zbigniew A. Łagodowski
Energies 2023, 16(20), 7117; https://doi.org/10.3390/en16207117 - 17 Oct 2023
Viewed by 900
Abstract
In this work, a new method for constructing the infinite-dimensional Ornstein–Uhlenbeck stochastic process is introduced. The constructed process is used to perturb the harmonic system in order to model anomalously fast heat transport in one-dimensional nanomaterials. The introduced method made it possible to [...] Read more.
In this work, a new method for constructing the infinite-dimensional Ornstein–Uhlenbeck stochastic process is introduced. The constructed process is used to perturb the harmonic system in order to model anomalously fast heat transport in one-dimensional nanomaterials. The introduced method made it possible to obtain a transition probability function that allows for a different approach to the analysis of equations with such a disturbance. This creates the opportunity to relax assumptions about temporal correlations for such a process, which may lead to a qualitatively different model of energy transport through vibrations of the crystal lattice and, as a result, to obtain the superdiffusion equation on a macroscopic scale with an order of the fractional Laplacian different from the value of 3/4 obtained so far in stochastic models. Simulations confirming these predictions are presented and discussed. Full article
(This article belongs to the Topic Thermal Energy Transfer and Storage)
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14 pages, 1345 KiB  
Article
Optimizing Energy Efficiency of Dielectric Materials’ Electrodischarge Dispersion as One Sustainable Development Green Trend
by Antonina Malyushevskaya, Serhii Petrychenko, Krzysztof Przystupa, Olena Mitryasova, Michał Majka and Orest Kochan
Energies 2023, 16(20), 7098; https://doi.org/10.3390/en16207098 - 15 Oct 2023
Viewed by 1491
Abstract
Increasing the energy efficiency of production processes is closely related to minimizing the impact on the environment and is one of the priorities of the concept of sustainable development. Electric discharge is an effective tool for multilevel grinding of non-metallic materials in various [...] Read more.
Increasing the energy efficiency of production processes is closely related to minimizing the impact on the environment and is one of the priorities of the concept of sustainable development. Electric discharge is an effective tool for multilevel grinding of non-metallic materials in various working fluids and obtaining coarse and fine suspensions. We introduce the technique for calculating the electrotechnological parameters necessary for energy-efficient electric discharge dispersion. This technique considers the strength characteristics of the crushed material (dispersed phase) and the electrical conductivity of the working fluid (dispersed medium). It is also essential to consider the energy stored in the capacitor bank, the energy criterion, the critical value of the working fluid’s electrical strength, the radius of the high-voltage electrode point, and the distance from the discharge channel axis to the disintegration object. All this allows obtaining a given granulometric composition of the dispersed phase with minimal energy consumption. Experiments confirmed the validity of the proposed calculation technique. We obtained the water-brown coal suspension with a given dispersion two times faster and consumed four times less energy in comparison with the known methods that did not take into account the electrical conductivity of the working liquid and the mechanical strength of the crushed material. Full article
(This article belongs to the Special Issue Emerging Topics in Future Energy Materials)
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15 pages, 1867 KiB  
Article
Limitations Imposed Using an Iodide/Triiodide Redox Couple in Solar-Powered Electrochromic Devices
by George Syrrokostas, Sarantis Tsamoglou and George Leftheriotis
Energies 2023, 16(20), 7084; https://doi.org/10.3390/en16207084 - 13 Oct 2023
Viewed by 1186
Abstract
In the present study, an iodide/triiodide (I−/I3−) redox couple is used in hybrid electrochromic devices (ECDs), and the effects of the applied bias potential and bias time on device performance are studied. An applied bias potential [...] Read more.
In the present study, an iodide/triiodide (I−/I3−) redox couple is used in hybrid electrochromic devices (ECDs), and the effects of the applied bias potential and bias time on device performance are studied. An applied bias potential of ~1 V is sufficient to achieve an initial contrast ratio of 8:1 in less than 5 min. Increasing both the bias potential and bias time results in an enhancement in loss reactions at the WO3/electrolyte interface, rather than improving optical performance. Moreover, long-term performance depends on the testing procedure (regularly cycling or after storage), while the formation of iodine (I2) decreases the initial transparency of the ECDs and affects their overall performance. However, its formation cannot be avoided, even without cycling the ECDs, and the restoration of the optical performance can take place only when the electrolyte is replaced with a fresh one. Finally, a new methodology is applied for calculating the loss current, and a suggestion is made to avoid a common mistake in calculating the coloration efficiency of these hybrid ECDs. Full article
(This article belongs to the Special Issue Smart Materials and Devices for Energy Saving and Harvesting)
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17 pages, 2791 KiB  
Article
Analysis of Frequency Regulation Capability of Doubly Fed Induction Generator and Supercapacitor Energy Storage Based on Dynamic Power Flow
by Tingting Sun, Hongru Shi, Lei Ren and Jiejie Huang
Energies 2023, 16(20), 7059; https://doi.org/10.3390/en16207059 - 12 Oct 2023
Viewed by 1018
Abstract
The grid-integrated doubly fed induction generator (DFIG) is required to participate in the frequency regulation of the power system. The supercapacitor energy storage (SES) is capable of enhancing the frequency regulation capability of the DFIG in a coupled manner. The SES is connected [...] Read more.
The grid-integrated doubly fed induction generator (DFIG) is required to participate in the frequency regulation of the power system. The supercapacitor energy storage (SES) is capable of enhancing the frequency regulation capability of the DFIG in a coupled manner. The SES is connected to the DC capacitor of the DFIG and provides active power response through the droop control. The dynamic power flow (DPF) model is established to quantify the frequency response of the power system when the DFIG-SES system participates in the frequency regulation. The integration of the SES affects the internal power flow distribution of the DFIG; thus, the detailed model of the DFIG is incorporated into the DPF analysis. Considering the different response speeds of the synchronous generator (SG), the SES, and the DFIG to the frequency regulation, the first-order inertia delay in the governor control of the SG is included in the DPF model. The impact of the delay time constant on the continued operation time of the SES is analyzed. With the same deloading percentage, the output power of the DFIG is adjusted based on a variable droop coefficient scheme to fully utilize its active power reserve. The feasibility and effectiveness of the DFIG-SES scheme to participate in the frequency regulation are analyzed based on the DPF and verified through numerical analysis. Full article
(This article belongs to the Collection Renewable Energy and Energy Storage Systems)
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21 pages, 4373 KiB  
Article
A Two-Terminal Directional Protection Method for HVDC Transmission Lines of Current Fault Component Based on Improved VMD-Hilbert Transform
by Shuhao Liu, Kunlun Han, Hongzheng Li, Tengyue Zhang and Fengyuan Chen
Energies 2023, 16(19), 6987; https://doi.org/10.3390/en16196987 - 7 Oct 2023
Cited by 1 | Viewed by 1123
Abstract
The traveling wave protection of high voltage direct current (HVDC) transmission lines is susceptible to the influence of transition resistance. As a backup protection, current differential protection has absolute selectivity, but usually requires an increase in delay to avoid misoperation caused by distributed [...] Read more.
The traveling wave protection of high voltage direct current (HVDC) transmission lines is susceptible to the influence of transition resistance. As a backup protection, current differential protection has absolute selectivity, but usually requires an increase in delay to avoid misoperation caused by distributed capacitance on the line, resulting in a longer action time. Based on this, a two-terminal directional protection method for HVDC transmission lines is proposed based on Sparrow Search Algorithm (SSA)-Variational Mode Decomposition (VMD) and Hilbert phase difference. On the basis of analyzing the directional characteristics of the current fault component at both ends of the rectifier and inverter sides under different faults, SSA is first used to optimize the parameters of VMD. The residual components representing the direction of the current fault component at both ends are extracted through VMD, and then the Hilbert phase difference of the residual components at both ends is calculated to identify faults inside and outside the line area. In addition, fault pole selection can be achieved based on the ratio of the sum of multi-band Hilbert energy of single-terminal voltage fault components at the positive and negative poles. Simulation experiments have shown that the proposed protection scheme can quickly and effectively identify fault and has good tolerance to transition resistance and noise interference. Full article
(This article belongs to the Special Issue Modeling, Simulation and Optimization of Power System)
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17 pages, 16478 KiB  
Article
Detection of Manufacturing Defects in Lithium-Ion Batteries-Analysis of the Potential of Computed Tomography Imaging
by Daniel Evans, Paul-Martin Luc, Claas Tebruegge and Julia Kowal
Energies 2023, 16(19), 6958; https://doi.org/10.3390/en16196958 - 5 Oct 2023
Cited by 1 | Viewed by 3750
Abstract
Realising an ideal lithium-ion battery (LIB) cell characterised by entirely homogeneous physical properties poses a significant, if not an impossible, challenge in LIB production. Even the slightest deviation in a process parameter in its production leads to inhomogeneities and causes a deviation in [...] Read more.
Realising an ideal lithium-ion battery (LIB) cell characterised by entirely homogeneous physical properties poses a significant, if not an impossible, challenge in LIB production. Even the slightest deviation in a process parameter in its production leads to inhomogeneities and causes a deviation in performance parameters of LIBs within the same batch. The greater the number and/or intensity of inhomogeneities, the more they need to be avoided. Severe inhomogeneities (defects), such as metal particle contamination, significantly impact the cell’s performance. Besides electrical measurements, image-based measurement methods can be used to identify defects and, thus, ensure the production quality and safety of LIBs. While the applicability of computed tomography (CT) as an image-based measurement method for detecting defects has been proven, the limitations of this method still need to be determined. In this study, a systematic analysis of the capabilities of CT imaging was conducted. A multilayer pouch cell without an electrolyte was reassembled with several defects on one of the middle anodes. To investigate the boundaries of CT, defects such as a partial and complete removal of the coating, a cut, or a kink, as well as particle contaminations of various sizes and materials (aluminium, copper, iron) were chosen. By comparing the CT images of the cell using laser scanning microscope images of the defective anode, it could be proven that all selected defects except the kink were detectable. Full article
(This article belongs to the Collection Renewable Energy and Energy Storage Systems)
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18 pages, 3573 KiB  
Article
Optimal Configuration of Power-to-Heat Equipment Considering Peak-Shaving Ancillary Service Market
by Yanjuan Yu, Guohua Zhou, Kena Wu, Cheng Chen and Qiang Bian
Energies 2023, 16(19), 6860; https://doi.org/10.3390/en16196860 - 28 Sep 2023
Cited by 3 | Viewed by 1039
Abstract
The serious problem of wind power curtailment in northern China has created a pressing need to enhance the peak-shaving ability of the power system. As the main source of power supply in northern China, combined heat and power (CHP) units have significant potential [...] Read more.
The serious problem of wind power curtailment in northern China has created a pressing need to enhance the peak-shaving ability of the power system. As the main source of power supply in northern China, combined heat and power (CHP) units have significant potential for peak-shaving. Currently, the Chinese government encourages CHP plants to increase their peak-shaving capacity by installing power-to-heat (P2H) equipment. In addition, the government has implemented auxiliary service market policies to encourage CHP plants to provide peak-shaving services. In order to maximize economic benefits for CHP plants, this paper proposes an optimal configuration method of P2H equipment with the static payback time (SPT) as the objective function. Cost and income models of installing the P2H equipment are constructed by taking into account the auxiliary service market policies. The peak-shaving income model of the CHP plant is derived emphatically as a key part of the proposed method. Finally, the district heating region in Jilin province is used as a case study example. The results show that adding the P2H equipment is significantly effective in improving the peak-shaving ability of CHP units, and investing in heat pumps is more cost-effective than electric boilers. The proposed method can be applied to other northern regions relying on CHP units for central heating, providing a valuable solution to the problem of wind power curtailment in these regions. Full article
(This article belongs to the Special Issue Advanced Engineering and Green Energy)
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20 pages, 9900 KiB  
Article
Locating Potential Run-of-River Hydropower Sites by Developing Novel Parsimonious Multi-Dimensional Moving Window (PMMW) Algorithm with Digital Elevation Models
by Ninad Bhagwat and Xiaobing Zhou
Energies 2023, 16(19), 6865; https://doi.org/10.3390/en16196865 - 28 Sep 2023
Viewed by 1232
Abstract
We developed a Parsimonious Multi-dimensional Moving Window (PMMW) algorithm that only requires Digital Elevation Model (DEM) data of a watershed to efficiently locate potentially optimal hydropower sites. The methodology requires only open source DEM data; therefore, it can be used even in remotest [...] Read more.
We developed a Parsimonious Multi-dimensional Moving Window (PMMW) algorithm that only requires Digital Elevation Model (DEM) data of a watershed to efficiently locate potentially optimal hydropower sites. The methodology requires only open source DEM data; therefore, it can be used even in remotest watersheds of the world where in situ measurements are scarce or not available at all. We used three parameters in this algorithm, and tested the method using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topography Mission (SRTM) derived DEMs. Our case study on the Morony Watershed, Montana, USA shows that (1) along with 6 out of the 7 existing hydropower plants being successfully located, 12 new potential hydropower sites were also identified, using a clearance of 1 km, diversion of 90 m, and Hydropower Index (HI) threshold of 109 m as the criteria. For the 12 new potential hydropower sites, 737.86 Megawatts (MW) ± 84.56 MW untapped hydropower potential in the Morony Watershed was also derived; (2) SRTM DEM is more suitable for determining the potential hydropower sites; (3) although the ASTER and SRTM DEMs provide elevation data with high accuracy, micro-scale elevation differences between them at some locations may have a profound impact on the HI. Full article
(This article belongs to the Section A3: Wind, Wave and Tidal Energy)
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19 pages, 13370 KiB  
Article
Experimental Study on Flame Response Characteristics of a Non-Premixed Swirl Model Combustor
by Chen Yang, Yong Liu, Xiang Zhang, Hao Li, Xinkun Ge, Feng Jin and Chongyang Liu
Energies 2023, 16(19), 6834; https://doi.org/10.3390/en16196834 - 27 Sep 2023
Cited by 2 | Viewed by 1327
Abstract
Non-premixed swirl combustion has been widely used in pieces of industrial combustion equipment such as industrial boilers, furnaces, and certain specific gas turbine combustors. In recent years, the combustion instability of non-premixed swirl flames has begun receiving attention, yet there is still a [...] Read more.
Non-premixed swirl combustion has been widely used in pieces of industrial combustion equipment such as industrial boilers, furnaces, and certain specific gas turbine combustors. In recent years, the combustion instability of non-premixed swirl flames has begun receiving attention, yet there is still a lack of related research in academia. Therefore, in this study, we conducted experimental research on a swirl stabilized gas flame model combustor and studied the heat release response characteristics of the swirl combustor through the flame transfer function. Firstly, the flame transfer function (FTF) was measured under different inlet velocities and equivalence ratios, and the experimental results showed that the FTF gain curve of the non-premixed swirl flame exhibited a significant “bimodal” shape, with the gain peaks located around 230 Hz and 330 Hz, respectively. Secondly, two oscillation modes of the flame near the two gain peaks were identified (the acoustic induced vortex mode Mv and the thermoacoustic oscillation mode Ma), which have not been reported in previous studies on swirl non-premixed flames. In addition, we comprehensively analyzed the flame pulsation characteristics under the two oscillation modes. Finally, the coupling degrees between velocity fluctuations, fuel pressure fluctuations, and heat release fluctuations were analyzed using the Rayleigh Index (RI), and it was found that in the acoustic-induced vortex mode, a complete feedback loop was not formed between the combustor and the fuel pipeline, which was the main reason for the significant difference in the pressure fluctuation amplitude near 230 Hz and 330 Hz. Full article
(This article belongs to the Section I2: Energy and Combustion Science)
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24 pages, 2836 KiB  
Article
The Carbon Footprint of Thermal Insulation: The Added Value of Circular Models Using Recycled Textile Waste
by Antonella Violano and Monica Cannaviello
Energies 2023, 16(19), 6768; https://doi.org/10.3390/en16196768 - 22 Sep 2023
Cited by 2 | Viewed by 2512
Abstract
The goal of climate neutrality by 2050 drives the building sector towards stricter control of processes and products, leading to a substantial reduction of embodied carbon throughout the life cycle. Many of the most used insulation materials have a high carbon footprint, mainly [...] Read more.
The goal of climate neutrality by 2050 drives the building sector towards stricter control of processes and products, leading to a substantial reduction of embodied carbon throughout the life cycle. Many of the most used insulation materials have a high carbon footprint, mainly due to the production phase (from cradle to gate). The need to reduce these impacts has led to the implementation of materials whose predominant raw material is recycled material in order to reduce the embodied carbon. The contribution presents the results of a research work that analysed the potential of insulation materials obtained from textile waste, evaluating not only their energy performance but also, above all, their environmental impact in terms of carbon footprint. It starts from a state-of-the-art analysis of the main traditional and new-generation thermal insulation materials, not only in relation to performance but also to environmental impacts, in order to investigate the opportunities offered using insulation materials designed according to circular models (10R) and produced with industrial and/or post-consumer waste fabrics, through a carbon footprint comparison. To support the choice of this type of insulation, a multi-criteria evaluation method is proposed through which the comparative analysis of the most significant insulation products selected is carried out. Full article
(This article belongs to the Special Issue Emerging Research on the Energy and Thermal-Hygrometric Optimization of Buildings and Related Systems)
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20 pages, 8993 KiB  
Article
Battery and Hydrogen Energy Storage Control in a Smart Energy Network with Flexible Energy Demand Using Deep Reinforcement Learning
by Cephas Samende, Zhong Fan, Jun Cao, Renzo Fabián, Gregory N. Baltas and Pedro Rodriguez
Energies 2023, 16(19), 6770; https://doi.org/10.3390/en16196770 - 22 Sep 2023
Cited by 5 | Viewed by 2219
Abstract
Smart energy networks provide an effective means to accommodate high penetrations of variable renewable energy sources like solar and wind, which are key for the deep decarbonisation of energy production. However, given the variability of the renewables as well as the energy demand, [...] Read more.
Smart energy networks provide an effective means to accommodate high penetrations of variable renewable energy sources like solar and wind, which are key for the deep decarbonisation of energy production. However, given the variability of the renewables as well as the energy demand, it is imperative to develop effective control and energy storage schemes to manage the variable energy generation and achieve desired system economics and environmental goals. In this paper, we introduce a hybrid energy storage system composed of battery and hydrogen energy storage to handle the uncertainties related to electricity prices, renewable energy production, and consumption. We aim to improve renewable energy utilisation and minimise energy costs and carbon emissions while ensuring energy reliability and stability within the network. To achieve this, we propose a multi-agent deep deterministic policy gradient approach, which is a deep reinforcement learning-based control strategy to optimise the scheduling of the hybrid energy storage system and energy demand in real time. The proposed approach is model-free and does not require explicit knowledge and rigorous mathematical models of the smart energy network environment. Simulation results based on real-world data show that (i) integration and optimised operation of the hybrid energy storage system and energy demand reduce carbon emissions by 78.69%, improve cost savings by 23.5%, and improve renewable energy utilisation by over 13.2% compared to other baseline models; and (ii) the proposed algorithm outperforms the state-of-the-art self-learning algorithms like the deep-Q network. Full article
(This article belongs to the Special Issue Advanced Artificial Intelligence Application for Power Systems)
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11 pages, 1934 KiB  
Article
Intrinsic Photoconductivity Spectral Dependence as a Tool for Prediction of Open-Circuit Voltage in Organic Solar Cells
by Raitis Grzibovskis, Andis Polaks and Aivars Vembris
Energies 2023, 16(18), 6728; https://doi.org/10.3390/en16186728 - 20 Sep 2023
Cited by 2 | Viewed by 1332
Abstract
Organic materials are known for their variety of molecules. Methods to predict the parameters of organic photovoltaic (OPV) cells are required to avoid the time- and resource-consuming processes of manufacturing and testing OPVs. Usually, the open-circuit voltage (Uoc) is estimated [...] Read more.
Organic materials are known for their variety of molecules. Methods to predict the parameters of organic photovoltaic (OPV) cells are required to avoid the time- and resource-consuming processes of manufacturing and testing OPVs. Usually, the open-circuit voltage (Uoc) is estimated as the difference between the ionization energy level of the electron donor molecule (Id) and the electron affinity level of the electron acceptor molecule (EAa). Various measurement methods are used to determine the energy level values of pure materials, which, when combined with energy level shifts due to the donor:acceptor interactions, make these estimations less precise. In this work, photoconductivity measurements were applied to the donor:acceptor films. Near threshold energy, the electron can be directly transferred from the donor to the acceptor molecule. The obtained charge transfer energy (ECT) shows the difference between Id and EAa in the film. This difference was compared to the Uoc value of an OPV made of the same donor:acceptor combination. We show that this approach provides less scattered results and a higher correlation coefficient compared to the Uoc estimation using energy level values. Full article
(This article belongs to the Special Issue Advances on Solar Energy Materials and Solar Cells)
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15 pages, 437 KiB  
Review
Anomaly Detection in Power System State Estimation: Review and New Directions
by Austin Cooper, Arturo Bretas and Sean Meyn
Energies 2023, 16(18), 6678; https://doi.org/10.3390/en16186678 - 18 Sep 2023
Cited by 4 | Viewed by 2440
Abstract
Foundational and state-of-the-art anomaly-detection methods through power system state estimation are reviewed. Traditional components for bad data detection, such as chi-square testing, residual-based methods, and hypothesis testing, are discussed to explain the motivations for recent anomaly-detection methods given the increasing complexity of power [...] Read more.
Foundational and state-of-the-art anomaly-detection methods through power system state estimation are reviewed. Traditional components for bad data detection, such as chi-square testing, residual-based methods, and hypothesis testing, are discussed to explain the motivations for recent anomaly-detection methods given the increasing complexity of power grids, energy management systems, and cyber-threats. In particular, state estimation anomaly detection based on data-driven quickest-change detection and artificial intelligence are discussed, and directions for research are suggested with particular emphasis on considerations of the future smart grid. Full article
(This article belongs to the Special Issue Climate Changes and the Impacts on Power and Energy Systems)
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12 pages, 1621 KiB  
Article
An Ensemble Approach for Intra-Hour Forecasting of Solar Resource
by Sergiu-Mihai Hategan, Nicoleta Stefu and Marius Paulescu
Energies 2023, 16(18), 6608; https://doi.org/10.3390/en16186608 - 14 Sep 2023
Cited by 2 | Viewed by 1032
Abstract
Solar resource forecasting is an essential step towards smart management of power grids. This study aims to increase the performance of intra-hour forecasts. For this, a novel ensemble model, combining statistical extrapolation of time-series measurements with models based on machine learning and all-sky [...] Read more.
Solar resource forecasting is an essential step towards smart management of power grids. This study aims to increase the performance of intra-hour forecasts. For this, a novel ensemble model, combining statistical extrapolation of time-series measurements with models based on machine learning and all-sky imagery, is proposed. This study is conducted with high-quality data and high-resolution sky images recorded on the Solar Platform of the West University of Timisoara, Romania. Atmospheric factors that contribute to improving or reducing the quality of forecasts are discussed. Generally, the statistical models gain a small skill score across all forecast horizons (5 to 30 min). The machine-learning-based methods perform best at smaller forecast horizons (less than 15 min), while the all-sky-imagery-based model performs best at larger forecast horizons. Overall, for forecast horizons between 10 and 30 min, the weighted forecast ensemble with frozen coefficients achieves a skill score between 15 and 20%. Full article
(This article belongs to the Special Issue Volume Ⅱ: Advances in Wind and Solar Farm Forecasting)
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27 pages, 9157 KiB  
Article
Heat Storage for Cooking: A Discussion on Requirements and Concepts
by Ole Jørgen Nydal
Energies 2023, 16(18), 6623; https://doi.org/10.3390/en16186623 - 14 Sep 2023
Cited by 1 | Viewed by 1887
Abstract
Methodologies for direct and indirect solar energy for cooking are discussed. Clean and renewable energy solutions for cooking are, in particular, in demand in the sub-Saharan region where fuel wood is the main source of energy for a large part of the population, [...] Read more.
Methodologies for direct and indirect solar energy for cooking are discussed. Clean and renewable energy solutions for cooking are, in particular, in demand in the sub-Saharan region where fuel wood is the main source of energy for a large part of the population, in particular in off-grid communities. As solar radiation is intermittent, energy storage solutions are required to provide cooking power during off-sun hours. Electrical batteries can be feasible for low-power applications (lights, electronics, and chargers) but tend to be costly and short-lived solutions for high-power cooking requirements. Heat battery concepts are discussed here together with prototype examples of latent and sensible heat storage solutions which have been laboratory tested for cooking and frying. Simplified computational comparisons between latent and sensible heat storage options show that oil and rock bed sensible heat systems, with a natural convection heat transfer, can be designed to provide variable cooking power levels. Oversized sensible heat storage systems can approach the near constant temperature and heat storage properties of a latent heat system. Latent heat storage systems can be more suitable for frying than for cooking applications. Full article
(This article belongs to the Special Issue Small Scale Solar Thermal Energy Storage Systems for Rural Energy)
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32 pages, 14330 KiB  
Review
A Review of Flywheel Energy Storage System Technologies
by Kai Xu, Youguang Guo, Gang Lei and Jianguo Zhu
Energies 2023, 16(18), 6462; https://doi.org/10.3390/en16186462 - 7 Sep 2023
Cited by 17 | Viewed by 9154
Abstract
The operation of the electricity network has grown more complex due to the increased adoption of renewable energy resources, such as wind and solar power. Using energy storage technology can improve the stability and quality of the power grid. One such technology is [...] Read more.
The operation of the electricity network has grown more complex due to the increased adoption of renewable energy resources, such as wind and solar power. Using energy storage technology can improve the stability and quality of the power grid. One such technology is flywheel energy storage systems (FESSs). Compared with other energy storage systems, FESSs offer numerous advantages, including a long lifespan, exceptional efficiency, high power density, and minimal environmental impact. This article comprehensively reviews the key components of FESSs, including flywheel rotors, motor types, bearing support technologies, and power electronic converter technologies. It also presents the diverse applications of FESSs in different scenarios. The progress of state-of-the-art research is discussed, emphasizing the use of artificial intelligence methods such as machine learning, digital twins, and data-driven techniques for system simulation, fault prediction, and life-assessment research. The article also addresses the challenges related to current research and the application of FESSs. It concludes by summarizing future directions and trends in FESS research, offering valuable information for further advancement and improvement in this field. Full article
(This article belongs to the Section D: Energy Storage and Application)
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17 pages, 4921 KiB  
Article
Current Pulse-Based Measurement Technique for Zinc–Air Battery Parameters
by Lin Hu and Xianzhi Xu
Energies 2023, 16(18), 6448; https://doi.org/10.3390/en16186448 - 6 Sep 2023
Viewed by 1579
Abstract
Zinc–air batteries possess advantages such as high energy density, low operational costs, and abundant reserves of raw materials, demonstrating broad prospects for applications in areas like stationary power supplies and emergency power sources. However, despite significant advancements in zinc–air battery technology, a comprehensive [...] Read more.
Zinc–air batteries possess advantages such as high energy density, low operational costs, and abundant reserves of raw materials, demonstrating broad prospects for applications in areas like stationary power supplies and emergency power sources. However, despite significant advancements in zinc–air battery technology, a comprehensive measurement model for zinc–air battery parameters is still lacking. This paper utilizes a gas diffusion model to separately calculate the concentration polarization of zinc–air batteries, decoupling it from electrochemical polarization and ohmic polarization, simplifying the equivalent circuit model of zinc–air batteries into a first-order RC circuit. Subsequently, based on the simplified equivalent circuit model and gas diffusion model, a zinc–air battery parameter measurement technique utilizing current pulse methods is proposed, with predictions made for the dynamic voltage response during current pulse discharges. Validation of this method was conducted through single current pulses and step current pulses. Experimental results demonstrate the method’s capability to accurately measure zinc–air battery parameters and predict the dynamic voltage response. Full article
(This article belongs to the Special Issue Advances in Modeling Methods for Battery Life Prediction and Performance Evaluation (Volume II))
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33 pages, 2788 KiB  
Review
From Lab to Fab: Development and Deployment of Direct Air Capture of CO2
by Vahid Barahimi, Monica Ho and Eric Croiset
Energies 2023, 16(17), 6385; https://doi.org/10.3390/en16176385 - 3 Sep 2023
Cited by 5 | Viewed by 7483
Abstract
Direct Air Capture (DAC) is a promising technology to fight climate change by capturing carbon dioxide (CO2) from the air. For DAC to be a negative emissions technology, the captured CO2 must be removed permanently, but can also be used [...] Read more.
Direct Air Capture (DAC) is a promising technology to fight climate change by capturing carbon dioxide (CO2) from the air. For DAC to be a negative emissions technology, the captured CO2 must be removed permanently, but can also be used as a net-zero technology to produce sustainable chemicals, fuels or other materials. This review presents a comprehensive survey of recent advancements, challenges, and potential applications of DAC technology, with an emphasis on the recent rapid increase in the number of DAC developers, the majority of them being founded in the past 4 years. Through pilot projects and recent commercial deployments, several DAC companies have made significant advances and demonstrated their scalability. Cost and energy efficiency remain significant impediments to the wide deployment of DAC. Integration with emission-free energy sources and utilization of waste heat are being researched to boost the total energy efficiency of DAC systems. Further research of electrochemical technologies for regeneration or direct capture are needed, as well as the development of new, modified, or hybrid adsorbents for improved capture efficiencies. Moreover, favorable regulations and financial incentives are crucial for enhancing the viability of DAC projects and will need to substantially increase if Paris Agreement goals are to be achieved. Full article
(This article belongs to the Collection Renewable Energy and Energy Storage Systems)
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30 pages, 1502 KiB  
Article
Evolutionary Analysis of the Solar Photovoltaic Products Trade Network in Belt and Road Initiative Countries from an Economic Perspective
by Liusuo Hu, Jian Hu and Weilung Huang
Energies 2023, 16(17), 6371; https://doi.org/10.3390/en16176371 - 2 Sep 2023
Cited by 3 | Viewed by 3250
Abstract
Against the backdrop of global energy transition and the imperative for sustainable development, the trade dynamics of solar photovoltaic (PV) products among “Belt and Road Initiative (BRI)” countries gained momentum. This study investigates the evolving trade patterns of PV products within BRI nations, [...] Read more.
Against the backdrop of global energy transition and the imperative for sustainable development, the trade dynamics of solar photovoltaic (PV) products among “Belt and Road Initiative (BRI)” countries gained momentum. This study investigates the evolving trade patterns of PV products within BRI nations, alongside the underlying determinants. The paper constructs and analyzes a solar PV product trade network, elucidating evolutionary trends, structural complexities, and clusters. A novel centrality influence model explores influencing factors across five dimensions. Methodologically, trade data, the “Five Connectivity” framework, and socio-economic indicators from 2001 to 2022 across 65 BRI countries underpin the study. Empirical insights reveal a robust PV product trade network with density exceeding 0.4 and reciprocity surpassing 0.38. China’s rising centrality, reflected in a weighted degree surge from 14.38 to 79.37 since 2011, signifies its consolidation within the network. Results show sustained high density and reciprocity in the PV trade network, signaling robust communication among BRI countries. China’s centrality in the network has consistently grown since 2011. Trade cluster analysis reveals isolated segments predominant, depicting emerging economies with limited photovoltaic exchanges, mainly export-focused. The study highlights the pivotal role of “Five Connectivity” dimensions in promoting PV trade, while financial connectivity’s impact remains modest. The emergence of PV product centers challenges traditional energy hubs, prompting the need for new energy trading paradigms and robust financial hubs. Full article
(This article belongs to the Collection Renewable Energy and Energy Storage Systems)
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23 pages, 5045 KiB  
Review
Enhancing Energy Efficiency and Building Performance through BEMS-BIM Integration
by Maria Kozlovska, Stefan Petkanic, Frantisek Vranay and Dominik Vranay
Energies 2023, 16(17), 6327; https://doi.org/10.3390/en16176327 - 31 Aug 2023
Cited by 7 | Viewed by 5654
Abstract
This paper presents a comprehensive analysis of the potential benefits and feasibility of integrating Building Energy Management Systems (BEMSs) with Building Information Modeling (BIM) in, but not limited to, the construction and building management sectors. By examining advantages, challenges, and real-world case studies, [...] Read more.
This paper presents a comprehensive analysis of the potential benefits and feasibility of integrating Building Energy Management Systems (BEMSs) with Building Information Modeling (BIM) in, but not limited to, the construction and building management sectors. By examining advantages, challenges, and real-world case studies, this study offers valuable insights into the impact of BEMS-BIM integration on building operations. The research methodology includes a literature review and bibliometric analysis to understand the subject domain and identify prevalent keywords. Additionally, case studies demonstrate the effectiveness of BEMS-BIM integration in real-world scenarios. This study investigates the possibilities and challenges of BIM to the BEMS methodology for energy-efficient industrial buildings, emphasizing the importance of addressing uncertainties and enhancing software interoperability. This research highlights the potential of BEMS-BIM integration to revolutionize building performance, enhance sustainability, and contribute to a greener and more efficient future for the construction and building management industries. Full article
(This article belongs to the Special Issue Energy Efficiency of the Buildings II)
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19 pages, 3515 KiB  
Review
The Role of the Energy Use in Buildings in Front of Climate Change: Reviewing a System’s Challenging Future
by George Ekonomou and Angeliki N. Menegaki
Energies 2023, 16(17), 6308; https://doi.org/10.3390/en16176308 - 30 Aug 2023
Cited by 6 | Viewed by 1639
Abstract
Energy keeps the global economy alive, while also being extensively exposed to various climate change impacts. In this context, severe business competition (e.g., the building sector) and the unwise use of natural resources and ecosystem services (e.g., fossil fuel energy sources) seem to [...] Read more.
Energy keeps the global economy alive, while also being extensively exposed to various climate change impacts. In this context, severe business competition (e.g., the building sector) and the unwise use of natural resources and ecosystem services (e.g., fossil fuel energy sources) seem to sharpen the relevant effects of climate change. Indicatively, contemporary issues at the interface of building energy performance and environmental quality levels include consequences from global warming, the increasing release of carbon dioxide to peak electrical loads, power grids, and building planning, and energy demand and supply issues. In light of such concerns, the present review paper attempts to disclose the multifaceted and multidisciplinary character of building energy use at the interface of the economy, the environment, and society against climate change. This review highlights energy efficiency concepts, production, distribution, consumption patterns, and relevant technological improvements. Interestingly, the reviewed contributions in the relevant literature reveal the need and necessity to alter the energy mix and relevant energy use issues. These include developments in climate-proof and effective systems regarding climate change impacts and shocks. Practical implications indicate that the sustainable development goals for clean energy and climate action should be followed if we wish to bring a sustainable future closer and faster to our reality. Full article
(This article belongs to the Special Issue Climate Changes and the Impacts on Power and Energy Systems)
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26 pages, 435 KiB  
Article
Design of Energy Communities and Data-Sharing: Format and Open Data
by Emanuele Guerrazzi, Dimitri Thomopulos, Davide Fioriti, Ivan Mariuzzo, Eva Schito, Davide Poli and Marco Raugi
Energies 2023, 16(17), 6268; https://doi.org/10.3390/en16176268 - 29 Aug 2023
Cited by 1 | Viewed by 2619
Abstract
Governments are promoting energy community (EC) policies to encourage joint investment and the operation of shared energy assets by citizens, industries, and public authorities, with the aim of promoting economic, social, and environmental benefits. However, ECs require appropriate planning and energy management strategies, [...] Read more.
Governments are promoting energy community (EC) policies to encourage joint investment and the operation of shared energy assets by citizens, industries, and public authorities, with the aim of promoting economic, social, and environmental benefits. However, ECs require appropriate planning and energy management strategies, which require data that are rarely clean and well-structured. Data providers rarely adhere to a common format for data sharing, which hinders the development of ECs. As the number of ECs is expected to grow significantly, this poses significant issues for stakeholders to quickly and efficiently develop projects. To address this issue, in this paper we propose a literature-based analysis and classification to derive the major data needs for EC planning, as well as a template format for data sharing. Our literature review on ECs successfully identifies the main data required to properly describe this system and its components. Their classification further clarifies that data structures shall account for tabular-like data of various types and flexible dimentionality, or cardinality. A public release of an open dataset for a case study in Pisa, Italy is also provided, supported by realistic or real data for testing the sizing and operation of ECs. The results suggest that data standard practices are needed, and this paper can lay the foundation for their standardization for ECs to fast-forward their deployment as support policy and technical decision-making. Full article
(This article belongs to the Special Issue Energy Communities Implementation)
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30 pages, 2522 KiB  
Review
Comprehensive Review and Analysis of Glazing Systems towards Nearly Zero-Energy Buildings: Energy Performance, Thermal Comfort, Cost-Effectiveness, and Environmental Impact Perspectives
by Saman Abolghasemi Moghaddam, Catarina Serra, Manuel Gameiro da Silva and Nuno Simões
Energies 2023, 16(17), 6283; https://doi.org/10.3390/en16176283 - 29 Aug 2023
Cited by 8 | Viewed by 3285
Abstract
The global interest in nearly zero-energy buildings (NZEBs) has led to their establishment as mandatory building objectives in Europe for all new constructions starting in 2021. The principles outlined in the Energy Performance of Building Directive (EPBD) emphasize the significance of reducing energy [...] Read more.
The global interest in nearly zero-energy buildings (NZEBs) has led to their establishment as mandatory building objectives in Europe for all new constructions starting in 2021. The principles outlined in the Energy Performance of Building Directive (EPBD) emphasize the significance of reducing energy demand through various energy efficiency measures to achieve NZEB status. Among these measures, the utilization of high-performance glazing systems plays a crucial role in ensuring natural light, ventilation, favorable solar gain, aesthetics, and positive psychological effects in buildings, while maintaining high energy performance and thermal comfort without burdening the budget or harming the environment. The use of increasingly larger glazing areas makes this topic of great relevance. Nevertheless, numerous studies frequently overlook certain crucial aspects of glazing systems in their assessments. This review study aims to assess different glazing solutions based on four critical perspectives called “EThCE”: Energy performance, thermal comfort, cost-effectiveness, and environmental impact, considering their interrelationships. Furthermore, the importance of adopting a comprehensive approach for selecting the optimal glazing solution for NZEBs is discussed. Additionally, the relationship between glazing systems and climate change is taken into account. Ultimately, the authors propose a comprehensive approach, including all the influential factors, to assist designers and homeowners in making informed decisions regarding glazing system selection for new NZEBs or NZEB retrofits in different situations. Full article
(This article belongs to the Special Issue Energy Efficiency of the Buildings II)
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27 pages, 5794 KiB  
Article
Mapping the Future of Green Hydrogen: Integrated Analysis of Poland and the EU’s Development Pathways to 2050
by Igor Tatarewicz, Sławomir Skwierz, Michał Lewarski, Robert Jeszke, Maciej Pyrka and Monika Sekuła
Energies 2023, 16(17), 6261; https://doi.org/10.3390/en16176261 - 28 Aug 2023
Cited by 3 | Viewed by 3245
Abstract
This article presents the results of a comparative scenario analysis of the “green hydrogen” development pathways in Poland and the EU in the 2050 perspective. We prepared the scenarios by linking three models: two sectoral models for the power and transport sectors, and [...] Read more.
This article presents the results of a comparative scenario analysis of the “green hydrogen” development pathways in Poland and the EU in the 2050 perspective. We prepared the scenarios by linking three models: two sectoral models for the power and transport sectors, and a Computable General Equilibrium model (d-Place). The basic precondition for the large-scale use of hydrogen, in both Poland and in European Union countries, is the pursuit of ambitious greenhouse gas reduction targets. The EU plans indicate that the main source of hydrogen will be renewable energy (RES). “Green hydrogen” is seen as one of the main methods with which to balance energy supply from intermittent RES, such as solar and wind. The questions that arise concern the amount of hydrogen required to meet the energy needs in Poland and Europe in decarbonized sectors of the economy, and to what extent can demand be covered by internal production. In the article, we estimated the potential of the production of “green hydrogen”, derived from electrolysis, for different scenarios of the development of the electricity sector in Poland and the EU. For 2050, it ranges from 76 to 206 PJ/y (Poland) and from 4449 to 5985 PJ/y (EU+). The role of hydrogen as an energy storage was also emphasized, highlighting its use in the process of stabilizing the electric power system. Hydrogen usage in the energy sector is projected to range from 67 to 76 PJ/y for Poland and from 1066 to 1601 PJ/y for EU+ by 2050. Depending on the scenario, this implies that between 25% and 35% of green hydrogen will be used in the power sector as a long-term energy storage. Full article
(This article belongs to the Special Issue Hydrogen and Fuel Cells Technologies for the Realisation of a Resilient and Zero-Carbon Economy)
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19 pages, 2296 KiB  
Review
Comprehensive Review of Liquid Air Energy Storage (LAES) Technologies
by Ayah Marwan Rabi, Jovana Radulovic and James M. Buick
Energies 2023, 16(17), 6216; https://doi.org/10.3390/en16176216 - 27 Aug 2023
Cited by 6 | Viewed by 6442
Abstract
In recent years, liquid air energy storage (LAES) has gained prominence as an alternative to existing large-scale electrical energy storage solutions such as compressed air (CAES) and pumped hydro energy storage (PHES), especially in the context of medium-to-long-term storage. LAES offers a high [...] Read more.
In recent years, liquid air energy storage (LAES) has gained prominence as an alternative to existing large-scale electrical energy storage solutions such as compressed air (CAES) and pumped hydro energy storage (PHES), especially in the context of medium-to-long-term storage. LAES offers a high volumetric energy density, surpassing the geographical constraints that hinder current mature energy storage technologies. The basic principle of LAES involves liquefying and storing air to be utilized later for electricity generation. Although the liquefaction of air has been studied for many years, the concept of using LAES “cryogenics” as an energy storage method was initially proposed in 1977 and has recently gained renewed attention. With the growing need for alternative energy storage methods, researchers have increasingly explored the potential of cryogenic media, leading to the development of the first LAES pilot plant and a growing body of research on LAES systems. However, one notable drawback of LAES is its relatively low round-trip efficiency, estimated to be around 50–60% for large-scale systems. However, due to its thermo-mechanical nature, LAES offers versatility and can be easily integrated with other thermal energy systems or energy sources across a wide range of applications. Most of the existing literature on LAES focuses on thermodynamic and economic analyses, examining various LAES configurations, and there is a clear lack of experimental studies in this field. This paper aims to conduct a comprehensive review of LAES technology, with a focus on the performance enhancement of these systems. Future perspectives indicate that hybrid LAES solutions, incorporating efficient waste energy recovery sections, hold the most promise for enhancing the tech-no-economic performance of standalone LAES systems. Full article
(This article belongs to the Special Issue Advances in Thermal Energy Storage and Applications)
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16 pages, 3870 KiB  
Article
Hydrous Pyrolysis of Source Rocks with Different Maturity in Dongying Sag, Bohai Bay Basin, China: Implications for Shale Oil Exploration and Development
by Jingong Cai, Chuan Cai, Longfei Lu, Qigui Jiang, Xiaoxiao Ma and Jinyi He
Energies 2023, 16(17), 6219; https://doi.org/10.3390/en16176219 - 27 Aug 2023
Cited by 1 | Viewed by 1211
Abstract
Shale oil yield, movability, and reservoir brittleness are three factors that must be focused on for shale oil exploration and development. The yield and composition of hydrocarbons and mineral composition have changed significantly during diagenesis, affecting the yield and movability of shale oil [...] Read more.
Shale oil yield, movability, and reservoir brittleness are three factors that must be focused on for shale oil exploration and development. The yield and composition of hydrocarbons and mineral composition have changed significantly during diagenesis, affecting the yield and movability of shale oil and the brittleness of the rock. In this study, the source rocks at different depths in the Dongying Sag were subjected to hydrous pyrolysis, and the yield and composition of pyrolyzed hydrocarbons and mineral composition were systematically analyzed. The brittleness index (BEI), weighted average specific surface area (SSAWA), and polarity index (PI) have been established to quantitatively characterize the brittleness and adsorption capacity of rock as well as the mobility of shale oil. The results suggest that diagenetic evolution controls rocks’ brittleness and adsorption capacity by changing their mineral composition. In the low-temperature stage, the mineral transformation is not obvious, and the BEI and SSAWA fluctuate in a small range. In the high-temperature stage, the rapid smectite illitization leads to an increase in the brittleness and a decrease in the adsorption capacity. In addition, the nonpolar components such as saturates and aromatics in the pyrolyzed hydrocarbons gradually increased with the increasing temperature, enhancing the mobility of the shale oil. Based on the three evaluation indexes of BEI, PI, and SSAWA, and combined with the changes in hydrocarbon yields during hydrous pyrolysis, we comparatively analyzed the differences in the mobility and yields of original soluble organic matter as well as pyrolyzed hydrocarbons of the source rocks at different depths. Based on the above results, it can be concluded that the shale in the depth range of 3300–3795 m is a favorable area for shale oil exploration and development in the study area. This work suggests that predicting the sweet spot for shale oil exploration and development requires more attention to the impact of diagenetic evolution on the composition of minerals and hydrocarbons. Full article
(This article belongs to the Special Issue Shale Lamina and Its Effect on Shale Oil Enrichment)
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29 pages, 5672 KiB  
Review
Green Hydrogen: Resources Consumption, Technological Maturity, and Regulatory Framework
by Jesús Rey, Francisca Segura and José Manuel Andújar
Energies 2023, 16(17), 6222; https://doi.org/10.3390/en16176222 - 27 Aug 2023
Cited by 13 | Viewed by 3615
Abstract
Current climate crisis makes the need for reducing carbon emissions more than evident. For this reason, renewable energy sources are expected to play a fundamental role. However, these sources are not controllable, but depend on the weather conditions. Therefore, green hydrogen (hydrogen produced [...] Read more.
Current climate crisis makes the need for reducing carbon emissions more than evident. For this reason, renewable energy sources are expected to play a fundamental role. However, these sources are not controllable, but depend on the weather conditions. Therefore, green hydrogen (hydrogen produced from water electrolysis using renewable energies) is emerging as the key energy carrier to solve this problem. Although different properties of hydrogen have been widely studied, some key aspects such as the water and energy footprint, as well as the technological development and the regulatory framework of green hydrogen in different parts of the world have not been analysed in depth. This work performs a data-driven analysis of these three pillars: water and energy footprint, technological maturity, and regulatory framework of green hydrogen technology. Results will allow the evaluation of green hydrogen deployment, both the current situation and expectations. Regarding the water footprint, this is lower than that of other fossil fuels and competitive with other types of hydrogen, while the energy footprint is higher than that of other fuels. Additionally, results show that technological and regulatory framework for hydrogen is not fully developed and there is a great inequality in green hydrogen legislation in different regions of the world. Full article
(This article belongs to the Section A5: Hydrogen Energy)
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20 pages, 4277 KiB  
Article
LCA and C-LCC Indicator as Tools for Sodium-Ion Batteries’ Eco-Design
by Maria Leonor Carvalho, Maria Anna Cusenza, Giulio Mela, Andrea Temporelli, Irene Quinzeni and Pierpaolo Girardi
Energies 2023, 16(17), 6220; https://doi.org/10.3390/en16176220 - 27 Aug 2023
Viewed by 1329
Abstract
Sodium-ion batteries are considered promising alternatives to lithium-ion technology; however, the diffusion on a commercial scale is hindered by the struggle to identify materials with high electrochemical performances. Studies available in the literature are mainly focused on electrochemical performance and neglect aspects related [...] Read more.
Sodium-ion batteries are considered promising alternatives to lithium-ion technology; however, the diffusion on a commercial scale is hindered by the struggle to identify materials with high electrochemical performances. Studies available in the literature are mainly focused on electrochemical performance and neglect aspects related to the environmental sustainability. In fact, the current state-of-the-art (presented in this study) shows that life cycle assessment (LCA) studies related to the production processes of electrode materials for Na-ion batteries are still very limited. The LCA methodology applied during the development of a technology phase can constitute a valid support for an eco-oriented design and, therefore, to the choice of solutions characterized by a lower environmental impact with the same electrochemical performance. In this context, a life cycle-based environmental–economic assessment was performed to evaluate the environmental impacts of the production process of cathode and anode materials for sodium-ion batteries. The study is focused on the cathodic active material Na0.66MnO2, considering two synthesis paths, and the anodic material consisting of tin (Sn) and Sn-carbon nanofiber (Sn-Cn) active material, binder, and other additives. Results illustrate the environmental performance of the different materials and constitute a useful input for their selection within an eco-design view. Full article
(This article belongs to the Special Issue Energy Storage: From Chemicals to Materials and More Ⅱ)
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24 pages, 9136 KiB  
Article
Low-Cost Maximum Power Point Tracking Strategy and Protection Circuit Applied to an Ayanz Wind Turbine with Screw Blades
by Aitor Arzuaga, Asier Estivariz, Oihan Fernández, Kristian Gubía, Ander Plaza, Gonzalo Abad and David Cabezuelo Romero
Energies 2023, 16(17), 6204; https://doi.org/10.3390/en16176204 - 26 Aug 2023
Cited by 1 | Viewed by 3492
Abstract
This paper provides three different research contributions applied to a Wind Turbine patented in 1606 by the inventor Jerónimo de Ayanz y Beaumont. The windmill under study is the Ayanz Wind Turbine with screw blades. The first contribution consists of an experimental characterization [...] Read more.
This paper provides three different research contributions applied to a Wind Turbine patented in 1606 by the inventor Jerónimo de Ayanz y Beaumont. The windmill under study is the Ayanz Wind Turbine with screw blades. The first contribution consists of an experimental characterization of the Ayanz Wind Turbine, incorporating the enclosure proposed at the patent and showing that the efficiency of the wind turbine is increased between 70% and 90% due to the enclosure being employed. As not many details about the shape of the screw blades are provided at the patent, in this article the nowadays well-studied and commercially available Archimedes Spiral Wind Turbine blade is utilized. It has been observed that by using an enclosure with a cylindrical shape, not only the efficiency of the wind turbine is increased, but the visual impact is reduced as seeing the blades rotating is avoided, which is a very important fact for many potential individual users of this wind turbine. In addition, it also enables the use of a protective mesh for birds, almost totally reducing the probability of bird deaths. The second contribution consists in a simple and low-cost Maximum Power Point Tracking (MPPT) strategy for the wind turbine, which only uses an AC three-phase impedance to capture the maximum energy from the wind, enabling to eliminate the DC-DC converter and microprocessor employed typically for this purpose. Due to this, the cost, complexity, failure rate, and power losses of the electronic power circuit are reduced which is very welcomed for small-scale wind turbines. Finally, the last contribution is a protection electronic circuit that fulfills several objectives: to brake the wind turbine under high winds and to disconnect and protect it when over-currents occur and when the voltage range of the batteries connected to the wind turbine is outside their safety range. Full article
(This article belongs to the Section A3: Wind, Wave and Tidal Energy)
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27 pages, 6070 KiB  
Review
PEM Fuel Cell Applications in Road Transport
by Antonio Nicolò Mancino, Carla Menale, Francesco Vellucci, Manlio Pasquali and Roberto Bubbico
Energies 2023, 16(17), 6129; https://doi.org/10.3390/en16176129 - 23 Aug 2023
Cited by 11 | Viewed by 5475
Abstract
Fuel cell electric vehicles represent a possible solution to meet the objectives of the energy transition currently underway, which sees the replacement of combustion vehicles with low environmental impact vehicles. For this reason, this market is expected to markedly grow in the coming [...] Read more.
Fuel cell electric vehicles represent a possible solution to meet the objectives of the energy transition currently underway, which sees the replacement of combustion vehicles with low environmental impact vehicles. For this reason, this market is expected to markedly grow in the coming years. Currently, the most suitable fuel cell technology for both light and heavy transport applications is the Proton Exchange Membrane fuel cell. This review provides a comprehensive description of the state of the art of fuel cell electric vehicles at different levels: vehicle configuration, fuel cell stack, and all the necessary operation systems. The current advantages and limits of the mentioned technology are highlighted, referring to recent studies aimed at optimizing the efficiency of the system and providing future perspectives. Full article
(This article belongs to the Special Issue Advances in Energy Storage Systems for Renewable Energy)
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20 pages, 1009 KiB  
Review
Quantifying Global Greenhouse Gas Emissions in Human Deaths to Guide Energy Policy
by Joshua M. Pearce and Richard Parncutt
Energies 2023, 16(16), 6074; https://doi.org/10.3390/en16166074 - 19 Aug 2023
Cited by 14 | Viewed by 66838
Abstract
When attempting to quantify future harms caused by carbon emissions and to set appropriate energy policies, it has been argued that the most important metric is the number of human deaths caused by climate change. Several studies have attempted to overcome the uncertainties [...] Read more.
When attempting to quantify future harms caused by carbon emissions and to set appropriate energy policies, it has been argued that the most important metric is the number of human deaths caused by climate change. Several studies have attempted to overcome the uncertainties associated with such forecasting. In this article, approaches to estimating future human death tolls from climate change relevant at any scale or location are compared and synthesized, and implications for energy policy are considered. Several studies are consistent with the “1000-ton rule,” according to which a future person is killed every time 1000 tons of fossil carbon are burned (order-of-magnitude estimate). If warming reaches or exceeds 2 °C this century, mainly richer humans will be responsible for killing roughly 1 billion mainly poorer humans through anthropogenic global warming, which is comparable with involuntary or negligent manslaughter. On this basis, relatively aggressive energy policies are summarized that would enable immediate and substantive decreases in carbon emissions. The limitations to such calculations are outlined and future work is recommended to accelerate the decarbonization of the global economy while minimizing the number of sacrificed human lives. Full article
(This article belongs to the Special Issue The Future of Energy Policy)
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19 pages, 4459 KiB  
Article
Adaptive Energy Management of Big Data Analytics in Smart Grids
by Rohit Gupta and Krishna Teerth Chaturvedi
Energies 2023, 16(16), 6016; https://doi.org/10.3390/en16166016 - 17 Aug 2023
Cited by 5 | Viewed by 3169
Abstract
The smart grid (SG) ensures the flow of electricity and data between suppliers and consumers. The reliability and security of data also play an important role in the overall management. This can be achieved with the help of adaptive energy management (AEM). This [...] Read more.
The smart grid (SG) ensures the flow of electricity and data between suppliers and consumers. The reliability and security of data also play an important role in the overall management. This can be achieved with the help of adaptive energy management (AEM). This research aims to highlight the big data issues and challenges faced by AEM employed in SG networks. In this paper, we will discuss the most commonly used data processing methods and will give a detailed comparison between the outputs of some of these methods. We consider a dataset of 50,000 instances from consumer smart meters and 10,000 attributes from previous fault data and 12 attributes. The comparison will tell us about the reliability, stability, and accuracy of the system by comparing the output of the various graphical plots of these methods. The accuracy percentage of the linear regression method is 98%; for the logistic regression method, it is 96%; and for K-Nearest Neighbors, it is 92%. The results show that the linear regression method applied gives the highest accuracy compared to logistic regression and K-Nearest Neighbors methods for prediction analysis of big data in SGs. This will ensure their use in future research in this field. Full article
(This article belongs to the Special Issue Advanced Machine Learning and Big Data Technologies for Smart Cities and Grids)
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16 pages, 4436 KiB  
Article
Power Smoothing Strategy for Wind Generation Based on Fuzzy Control Strategy with Battery Energy Storage System
by Pablo L. Tabosa da Silva, Pedro A. Carvalho Rosas, José F. C. Castro, Davidson da Costa Marques, Ronaldo R. B. Aquino, Guilherme F. Rissi, Rafael C. Neto and Douglas C. P. Barbosa
Energies 2023, 16(16), 6017; https://doi.org/10.3390/en16166017 - 17 Aug 2023
Cited by 8 | Viewed by 1575
Abstract
This work discusses the use of a battery energy storage system applied to the smoothing of power generated at the output of wind turbines based on a fuzzy logic power control. The fuzzy control logic proposed can perform the aforementioned activity while the [...] Read more.
This work discusses the use of a battery energy storage system applied to the smoothing of power generated at the output of wind turbines based on a fuzzy logic power control. The fuzzy control logic proposed can perform the aforementioned activity while the state of charge of the energy storage system is maintained within operational limits. In order to assess the fuzzy logic power control’s effectiveness at maintaining the state of charge levels within the allowed range, two operating situations are explored: one in which the state of charge is above the upper limit allowed, and another in which the state of charge is in the minimum value allowed. The numerical results show that, when using the battery energy storage system in conjunction with the control logic proposed, the active power provided as the point of common coupling by the wind turbines can be smoothed, thus contributing to the Electric Power System reliability and stability. The main results of this paper are based on measurements of wind and active power associated with a wind generation plant installed in the northeast region of Brazil and equipped with 2.1 MW wind turbines. Full article
(This article belongs to the Special Issue Applications of Battery Energy Storage Systems (BESS))
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19 pages, 17433 KiB  
Article
Electric Analysis of the Maritime Application High-Frequency Magnetohydrodynamic Thruster
by Kin Lung Jerry Kan, Ka Wai Eric Cheng and Hai-Chen Zhuang
Energies 2023, 16(16), 6021; https://doi.org/10.3390/en16166021 - 17 Aug 2023
Cited by 3 | Viewed by 1929
Abstract
A magnetohydrodynamic (MHD) thruster is the next-generation electric jet engine for maritime applications. It eliminates the moving mechanical components that make the noises and reduces physical harm to sea creatures. This paper finds that aluminum electrodes have higher conductivity and less capacitive value [...] Read more.
A magnetohydrodynamic (MHD) thruster is the next-generation electric jet engine for maritime applications. It eliminates the moving mechanical components that make the noises and reduces physical harm to sea creatures. This paper finds that aluminum electrodes have higher conductivity and less capacitive value in a KCl solution than the 316 stainless steel and zinc in MHD applications. Further, the AC operation can mitigate the power loss during electrolysis and power loss while on the water. The new optimal coil design with the enclosed-type ferrite layout of the MHD thruster is addressed by this simulation study. The AC operation and electric drive with a Lorentz force analysis will be demonstrated. Lastly, a verification experiment that pushes the KCl solution at 3 cm/s will be interpreted by the prototype to display the electric operation detail. Full article
(This article belongs to the Topic Advanced Electric Vehicle Technology)
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17 pages, 6962 KiB  
Article
Partial Discharge-Originated Deterioration of Insulating Material Investigated by Surface-Resistance and Potential Mapping
by Marek Florkowski and Maciej Kuniewski
Energies 2023, 16(16), 5973; https://doi.org/10.3390/en16165973 - 14 Aug 2023
Cited by 3 | Viewed by 1948
Abstract
The endurance of medium- and high-voltage electrical insulation is a key reliability element in a broad spectrum of applications that cover transmission and distribution levels, the transportation segment, the industrial environment, and power electronics-based energy-conversion systems. The high electric-field stress and high-frequency switching [...] Read more.
The endurance of medium- and high-voltage electrical insulation is a key reliability element in a broad spectrum of applications that cover transmission and distribution levels, the transportation segment, the industrial environment, and power electronics-based energy-conversion systems. The high electric-field stress and high-frequency switching phenomena as well as the impact of environmental conditions lead to the occurrence of partial discharges (PD) and the subsequent deterioration of electrical insulation. Partial discharges usually occur inside solid insulation materials in tiny voids that may either be located adjacent to the electrodes or in the bulk of dielectric material. This effect refers to both AC and DC systems; however, AC voltage is usually much more intensive as compared to DC voltage. This paper describes a novel combined approach based on surface-resistance and potential mapping to reveal the effects of internal processes and the deterioration of insulating material due to the actions of partial discharges. To realize the research objective, the following two-step approach was proposed. Multi-point resistance mapping enables us to identify the spots of discharge channels, manifesting a-few-orders-of-magnitude-lower surface resistance as compared to untreated areas. In addition, surface-potential mapping that was stimulated by corona-charge deposition reflects quasi-equipotential clusters and the related polarity-dependent dynamics of charge decay. A high spatial and temporal resolution allows for the precise mapping and tracing of decay patterns. Experiments were carried out on polyethylene (PE) and Nomex specimens that contained embedded voids. During PD events, the effective discharge areas are identified along with the memory effects that originate from the accumulation of surface charges. Long-term aging processes may drive the formation of channels that are initiated from the deteriorated micro clusters, in turn, penetrating the bulk isolation. The presented methodology and experimental results extend the insight into PD mechanisms and internal surface processes. Full article
(This article belongs to the Special Issue Dielectric Insulation in Medium- and High-Voltage Power Equipment—Degradation and Failure Mechanism, Diagnostics, and Electrical Parameters Improvement)
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19 pages, 5510 KiB  
Review
A Review on Dry Deposition Techniques: Pathways to Enhanced Perovskite Solar Cells
by Jae-Keun Hwang, Seok-Hyun Jeong, Donghwan Kim, Hae-Seok Lee and Yoonmook Kang
Energies 2023, 16(16), 5977; https://doi.org/10.3390/en16165977 - 14 Aug 2023
Cited by 2 | Viewed by 2813
Abstract
This review discusses the use of evaporation, chemical vapor deposition, and sputtering as the three main dry deposition techniques currently available for fabricating perovskite solar cells. We outline the distinct advantages that each method offers in terms of film quality, control, and scalability. [...] Read more.
This review discusses the use of evaporation, chemical vapor deposition, and sputtering as the three main dry deposition techniques currently available for fabricating perovskite solar cells. We outline the distinct advantages that each method offers in terms of film quality, control, and scalability. Additionally, recent advancements in process optimization and the integration of dry deposition with other fabrication techniques are highlighted. Thus, this review provides valuable insights into the potential of dry deposition processes to produce high-performance perovskite solar cells and aids researchers and industry professionals in selecting the most suitable technique for the fabrication of efficient and stable devices. Full article
(This article belongs to the Special Issue Advanced Technologies of Solar Cells)
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